CVE-2025-38433 is a medium severity vulnerability in the Linux kernel affecting riscv nommu kernels. The issue arises from improper handling of zero values in the __runtime_fixup_32 function, which can cause invalid pointers and kernel panic. This occurs because the function may emit two nop instructions, leaving garbage in registers that leads to invalid pointer dereference. The flaw has been fixed by adjusting the patching logic to correctly handle cases where instructions are converted to nops.